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purity

Page 26 of 33 · 788 questions tagged purity.

788 questions · sorted by votes · page 26 of 33

10 votes 4 answers7.7k views
What does 97.9% purity on a C18 column actually tell me about an ecnoglutide vial?

What I am working with: 97.9% · a C18 column · ecnoglutide. I would like help reading this properly rather than being told what conclusion to reach. I have the full…

hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

466 questions
purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

749 questions
asked by valentina_rossi 16k · 10 months ago
10 votes 3 answers7.4k views
What counter-ion should I expect on an ERP cagrilintide lot?

Setup, so nobody has to ask: ERP · cagrilintide. I have read the primary source rather than the summary, which has left me with more questions. I understand the…

acetate-content
acetate-content

Counter-ion content, most often acetate or trifluoroacetate, and why it matters: the counter-ion and residual water are part of the gross mass you…

87 questions
purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
content-assay
content-assay

Quantified content: how many milligrams of peptide are actually in the vial, measured against a calibrated reference standard. A separate test…

438 questions
asked by elke_brunner 14k · 4 months ago
10 votes 3 answers7.1k views
Why would Medutest report 98.8% where the supplier certificate says something higher?

Details up front: Medutest · 98.8%. I have a result I cannot explain, and I would rather diagnose it than guess. I have checked the obvious explanations and…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

466 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

865 questions
asked by meniscus_film 34k · 4 months ago
10 votes 4 answers7k views
What does a 97.1% purity with a batch certificate attached let me conclude?

Setup, so nobody has to ask: 97.1% · batch certificate. I have read the primary source rather than the summary, which has left me with more questions. I understand…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

749 questions
hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

466 questions
asked by siobhan_deasy 16k · 6 months ago
10 votes 1 answer6.9k views
What counter-ion should I expect on a WWB orforglipron lot?

Details up front: WWB · orforglipron. This is presented as though it settles something, and I am not convinced it does. I have two documents that appear to disagree,…

acetate-content
acetate-content

Counter-ion content, most often acetate or trifluoroacetate, and why it matters: the counter-ion and residual water are part of the gross mass you…

87 questions
purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
content-assay
content-assay

Quantified content: how many milligrams of peptide are actually in the vial, measured against a calibrated reference standard. A separate test…

438 questions
asked by nkem_obiora 46k · 12 months ago
10 votes 5 answers4.7k views
Is 95.2% a realistic purity ceiling for mazdutide given its chain length?

What I am working with: 95.2% · mazdutide. The units are where I keep going wrong, so please be explicit about them. I have sanity-checked the order of magnitude and…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

466 questions
peptide-mapping
peptide-mapping

Enzymatic digestion followed by LC-MS/MS to confirm sequence rather than just mass. The method that catches a scrambled sequence or a D-amino-acid…

83 questions
asked by Dr_Fatima_Belkacem 52k · 42 days ago
10 votes 3 answers4.6k views
What does a 97.9% purity with a batch certificate attached let me conclude?

Stated plainly: 97.9% · batch certificate. I have read the primary source rather than the summary, which has left me with more questions. I understand the headline. I…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

749 questions
hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

466 questions
asked by kelvin_lam 11k · 2 months ago
10 votes5 answers2.6k views
How do I reconcile 95.2% from Medutest with 97.1% from the supplier?

Setup, so nobody has to ask: 95.2% · Medutest · 97.1%. I noticed this today and I have not touched anything since, in case the state is diagnostic. I have not…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

865 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

749 questions
asked by mz_4113 99k · 3 months ago
10 votes0 answers1.3k views
Does aggregation of mazdutide at 2–8 °C show up as a loss of content or of purity?

What I am working with: aggregation · mazdutide · 2–8 °C. The empirical answer seems settled. The explanation does not. If the honest answer is that nobody knows, I…

peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
content-assay
content-assay

Quantified content: how many milligrams of peptide are actually in the vial, measured against a calibrated reference standard. A separate test…

438 questions
purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
asked by Dr_Ilse_Vandenberg 78k · 34 days ago
9 votes 5 answers34k views
How does reference-standard error propagate into an oral semaglutide content figure?

I have the report as a PDF with the chromatogram on page two, so I can quote specifics. I would like the arithmetic checked rather than the conclusion asserted. I…

reference-standard
reference-standard

Certified reference materials and in-house standards: traceability, the certificate of the standard itself, system suitability, and why every…

179 questions
content-assay
content-assay

Quantified content: how many milligrams of peptide are actually in the vial, measured against a calibrated reference standard. A separate test…

438 questions
purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
asked by jana_horakova 15k · 2.3 years ago
9 votes5 answers30k views
Would you accept 97.6% on survodutide from SWB without a content assay?

The particulars: 97.6% · survodutide · SWB. I am at the decision point and I would rather think it through than improvise. I would rather spend money on measurement…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
content-assay
content-assay

Quantified content: how many milligrams of peptide are actually in the vial, measured against a calibrated reference standard. A separate test…

438 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

436 questions
asked by assay_blank 39k · 2.0 years ago
9 votes 5 answers29k views
What does a sterility test add for orforglipron that a purity figure does not?

Details up front: a sterility test · orforglipron. I want to know what the trade-off actually is rather than which option is fashionable. I would rather have a…

content-assay
content-assay

Quantified content: how many milligrams of peptide are actually in the vial, measured against a calibrated reference standard. A separate test…

438 questions
purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

749 questions
asked by valentina_rossi 16k · 2.2 years ago
9 votes 4 answers22k views
Would you accept 97.9% on ecnoglutide from WWB without a content assay?

The particulars: 97.9% · ecnoglutide · WWB. I would like to define my thresholds before I have a result, for obvious reasons. I want a plan with explicit stopping…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
content-assay
content-assay

Quantified content: how many milligrams of peptide are actually in the vial, measured against a calibrated reference standard. A separate test…

438 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

436 questions
asked by carys_meredith 17k · 23 months ago
9 votes 3 answers19k views
Is a 98.4% result from Janoshik comparable to 98.2% from Medutest?

Details up front: 98.4% · Janoshik · 98.2% · Medutest. I want to know what the trade-off actually is rather than which option is fashionable. I would rather have a…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

865 questions
reference-standard
reference-standard

Certified reference materials and in-house standards: traceability, the certificate of the standard itself, system suitability, and why every…

179 questions
asked by dead_volume 49k · 20 months ago
9 votes5 answers18k views
How does cagrilintide behave on a C8 column compared to tirzepatide?

Details up front: cagrilintide · a C8 column · tirzepatide. I have used one of these for a while and I am considering switching, which requires a reason. What I care…

hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

466 questions
purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
reference-standard
reference-standard

Certified reference materials and in-house standards: traceability, the certificate of the standard itself, system suitability, and why every…

179 questions
asked by fib4_reader 35k · 2.2 years ago
9 votes 5 answers16k views
What does 98.8% purity on a C8 column actually tell me about an oral semaglutide vial?

What I have: 98.8% · a C8 column · oral semaglutide. I can parse the result. I am less sure what it licenses me to conclude. I have deliberately not looked at anyone…

hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

466 questions
purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

749 questions
asked by Dr_Tomas_Kral 37k · 23 months ago
9 votes5 answers15k views
Would you accept 95.2% on tirzepatide from ERP without a content assay?

Conditions: 95.2% · tirzepatide · ERP. I want to decide this in advance so that I am not deciding it under pressure later. Assume I will follow the plan I write down,…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
content-assay
content-assay

Quantified content: how many milligrams of peptide are actually in the vial, measured against a calibrated reference standard. A separate test…

438 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

436 questions
asked by haze_check 17k · 14 months ago
9 votes 5 answers11k views
How does tirzepatide behave on a wide-pore C18 column compared to mazdutide?

The specifics, since they change the answer: tirzepatide · a wide-pore C18 column · mazdutide. The comparison I want does not seem to exist anywhere in a form I can…

hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

466 questions
purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
reference-standard
reference-standard

Certified reference materials and in-house standards: traceability, the certificate of the standard itself, system suitability, and why every…

179 questions
asked by ilaria_bertone 43k · 9 months ago
9 votes4 answers10k views
Does deamidation of semaglutide at minus 20 °C show up as a loss of content or of purity?

The particulars: deamidation · semaglutide · minus 20 °C. I understand the observation; what I do not understand is the mechanism behind it. I have read the two…

peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
content-assay
content-assay

Quantified content: how many milligrams of peptide are actually in the vial, measured against a calibrated reference standard. A separate test…

438 questions
purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
asked by Dr_Jonas_Halvorsen 41k · 9 months ago
9 votes0 answers8.8k views
Is 99.1% a realistic purity ceiling for mazdutide given its chain length?

Stated plainly: 99.1% · mazdutide. The units are where I keep going wrong, so please be explicit about them. I have sanity-checked the order of magnitude and it seems…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

466 questions
peptide-mapping
peptide-mapping

Enzymatic digestion followed by LC-MS/MS to confirm sequence rather than just mass. The method that catches a scrambled sequence or a D-amino-acid…

83 questions
asked by esther_vandeVelde 49k · 15 months ago
9 votes 5 answers6.9k views
Does a TFA counter-ion show up in a purity number or a content number?

The method section is present, which is unusual enough that I want to make use of it. I have read the primary source rather than the summary, which has left me with…

acetate-content
acetate-content

Counter-ion content, most often acetate or trifluoroacetate, and why it matters: the counter-ion and residual water are part of the gross mass you…

87 questions
purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
content-assay
content-assay

Quantified content: how many milligrams of peptide are actually in the vial, measured against a calibrated reference standard. A separate test…

438 questions
asked by a_lindgren 46k · 8 months ago
9 votes5 answers6.4k views
Would you accept 98.2% on orforglipron from MKM without a content assay?

Details up front: 98.2% · orforglipron · MKM. I would rather over-plan the first cycle and simplify later. I am prepared to do the work if someone can tell me which…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
content-assay
content-assay

Quantified content: how many milligrams of peptide are actually in the vial, measured against a calibrated reference standard. A separate test…

438 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

436 questions
asked by lucia_marchetti 18k · 5 months ago
9 votes5 answers5.8k views
Is a 95.2% result from VendorInvestigate comparable to 96.4% from Janoshik?

The case in front of me: 95.2% · VendorInvestigate · 96.4% · Janoshik. I would like the axes of comparison first and the recommendation second. I have tried the first…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

865 questions
reference-standard
reference-standard

Certified reference materials and in-house standards: traceability, the certificate of the standard itself, system suitability, and why every…

179 questions
asked by ten_mg_vial 16k · 8 months ago
9 votes5 answers5.8k views
Is a 96.4% result from PeptideMeter comparable to 95.2% from Medutest?

For reference: 96.4% · PeptideMeter · 95.2% · Medutest. I am trying to choose between two options that are usually discussed as though only one exists. I am not…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

865 questions
reference-standard
reference-standard

Certified reference materials and in-house standards: traceability, the certificate of the standard itself, system suitability, and why every…

179 questions
asked by seamus_brady 17k · 5 months ago